But there are Dungeons and Dragons or Pathfinder ones sometimes and Harry Potter if that counts. There's a Pathfinder game here that's been going for like a year, pretty impressive.
Replied to you in the Discord, but both links are in my profile here too.
You should be fine. Fantasy and SciFi are both very popular here.
There are often several RPs going in the worlds of...
Elder Scrolls Harry Potter The Witcher Lord of the Rings Warhammer Fantasy Warhammer 40K Fallout Marvel or DC Comics
There are also often some original settings in the SciFi or Fantasy genre. Particularly in the Pen and Paper section but also in Advanced/Casual there are sometimes Dungeons and Dragons or Pathfinder based RPs.
I have not personally seen one yet but likely before too long there will be a Starfield RP if you are interested in that.
And as always if you don't see an RP set in the setting you would like it can't hurt to write up an Interest Check and start up your own.
Probably either the Punisher or Daredevil Netflix series.
Damn shame Marvel didn't hire those guys to do an actual Capt A & Bucky show or really any of the Marvel shows other than Loki, which I thought was ok.
I've done a few via Discord. It's imperfect but it allows for quick posting back and forth, gathering a lot of like minded folks fairly quickly, and doesn't have any of the "must be halfway advertiser friendly" restrictions or forums.
I've done Discord RPs for Tournament fighting and for Pen and Paper Roleplaying, like Dungeons and Dragons.
Check some of the links down below this post. The first one is just self promotion but the others are helpful.
Written by several different folks here they should help get back into the flow and explain a bit of the sort of culture here. Maybe help you figure out where you want to write as far as Advanced/Casual/Free.
Cheers bro. There's plenty of RPs here, you'll find your niche.